Employee Benefits - Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Employee Benefits
Options Outstanding, Number	152,500	140,500	148,000	104,000
Options Outstanding, Weighted Average Exercise Price	$ 42.76	$ 34.43	$ 39.63	$ 36.56
Options Exercisable, Number	88,500	65,800	63,700
Options Exercisable, Weighted Average Exercise Price	$ 39.51	$ 38.44	$ 33.89
31 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	31 months
Options Outstanding, Number	11,500
Options Outstanding, Weighted Average Exercise Price	$ 37.31
Options Exercisable, Number	11,500
Options Exercisable, Weighted Average Exercise Price	$ 37.31
42 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	42 months
Options Outstanding, Number	15,500
Options Outstanding, Weighted Average Exercise Price	$ 34.35
Options Exercisable, Number	15,500
Options Exercisable, Weighted Average Exercise Price	$ 34.35
56 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	56 months
Options Outstanding, Number	15,500
Options Outstanding, Weighted Average Exercise Price	$ 37.4
Options Exercisable, Number	15,500
Options Exercisable, Weighted Average Exercise Price	$ 37.4
67 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	67 months
Options Outstanding, Number	23,000
Options Outstanding, Weighted Average Exercise Price	$ 34.91
Options Exercisable, Number	18,400
Options Exercisable, Weighted Average Exercise Price	$ 34.91
79 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	79 months
Options Outstanding, Number	11,500
Options Outstanding, Weighted Average Exercise Price	$ 53.82
Options Exercisable, Number	6,900
Options Exercisable, Weighted Average Exercise Price	$ 53.82
85 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	85 months
Options Outstanding, Number	7,500
Options Outstanding, Weighted Average Exercise Price	$ 46.59
Options Exercisable, Number	3,000
Options Exercisable, Weighted Average Exercise Price	$ 46.59
92 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	92 months
Options Outstanding, Number	32,500
Options Outstanding, Weighted Average Exercise Price	$ 46.94
Options Exercisable, Number	13,000
Options Exercisable, Weighted Average Exercise Price	$ 46.94
99 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	99 months
Options Outstanding, Number	3,500
Options Outstanding, Weighted Average Exercise Price	$ 40.28
Options Exercisable, Number	700
Options Exercisable, Weighted Average Exercise Price	$ 40.28
103 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	103 months
Options Outstanding, Number	20,000
Options Outstanding, Weighted Average Exercise Price	$ 40.82
Options Exercisable, Number	4,000
Options Exercisable, Weighted Average Exercise Price	$ 40.82
116 mo.
Employee Benefits
Weighted Average Remaining Contractual Life	116 months
Options Outstanding, Number	12,000
Options Outstanding, Weighted Average Exercise Price	$ 60.42
Options Exercisable, Weighted Average Exercise Price	$ 60.42